scholarly journals Genetic diversity among toxigenic and nontoxigenicVibrio choleraeO1 isolated from the Western Hemisphere

1991 ◽  
Vol 107 (1) ◽  
pp. 225-233 ◽  
Author(s):  
F. Chen ◽  
G. M. Evins ◽  
W. L. Cook ◽  
R. Almeida ◽  
N. Hargrett-Bean ◽  
...  
Keyword(s):  
Gulf Coast ◽  
Genetic Relationships ◽  
Western Hemisphere ◽  
Enzyme Electrophoresis ◽  
Multilocus Enzyme Electrophoresis ◽  
The Us ◽  
Single Clone ◽  
Diverse Origin ◽  
Toxigenic Strains ◽  
Surrounding Areas

SUMMARYMultilocus enzyme electrophoresis was used to examine genetic relationships among and between toxigenic and non-toxigenic isolates ofVibrio choleraeO1 obtained from patients and the environment in the US Gulf Coast and surrounding areas. A total of 23 toxigenic and 23 non-toxigenic strains were examined. All the toxigenic and 7 of the non-toxigenic strains had the same alleles at 16 enzyme loci, whereas the balance of the nontoxigenic strains had 9 distinct combinations of alleles. This study suggests that all of the toxigenic strains belong to a single clone, and that while some of the non-toxigenic isolates were related, most were of diverse origin.

scholarly journals Genetic Heterogeneity of Strains of Neisseria meningitidis Belonging to Serotype 22 Isolated in the Czech Republic

1998 ◽  
Vol 36 (2) ◽  
pp. 563-565 ◽  
Author(s):  
Martin Musilek ◽  
Dario Giorgini ◽  
Nora Hamadouche ◽  
Paula Kriz ◽  
Muhamed-Kheir Taha
Keyword(s):  
Czech Republic ◽  
Neisseria Meningitidis ◽  
Genetic Heterogeneity ◽  
Genetic Relationships ◽  
Heterogeneous Population ◽  
Enzyme Electrophoresis ◽  
The Czech Republic ◽  
Multilocus Enzyme Electrophoresis ◽  
Single Clone ◽  
Electrophoresis Technique

Strains of Neisseria meningitidis of serogroup B isolated in the Czech Republic frequently belong to serotype 22. We analyzed the genetic relationships among strains of this serotype by using the multilocus enzyme electrophoresis technique and the polymorphism of the pilA gene. Our results indicate that these strains correspond to a highly heterogeneous population rather than to the expansion of a single clone.

scholarly journals Genetic characterization ofMycobacterium aviumisolates recovered from humans and animals in Australia

1996 ◽  
Vol 116 (1) ◽  
pp. 41-49 ◽  
Author(s):  
M. M. Feizabadi ◽  
I. D. Robertson ◽  
D. V. Cousins ◽  
D. Dawson ◽  
W. Chew ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mycobacterium Avium ◽  
Gel Electrophoresis ◽  
Genetic Characterization ◽  
Genetic Relationships ◽  
Pulsed Field Gel Electrophoresis ◽  
Pfge Type ◽  
Enzyme Electrophoresis ◽  
Pulsed Field ◽  
Multilocus Enzyme Electrophoresis

SummaryGenetic relationships amongst 115 mainly Australian isolates ofMycobacterium aviumwere assessed using multilocus enzyme electrophoresis (MEE). The isolates were divided into 58 electrophoretic types (ETs), with a mean genetic diversity of 0·29. Isolates from humans were closely related to but distinct from those cultured from birds, whilst some porcine isolates belonged to the same ETs as certain human isolates. Pulsed field gel electrophoresis (PFGE) was used to differentiate related isolates, and those from birds and some from other animals, including pigs, were distinguished from the human isolates. The results of MEE and PFGE suggested that certain strains ofM. aviummay be transmitted between birds and pigs, but there was no clear evidence of transmission to humans. The serovar of theM. aviumisolates was not obviously related to their ET assignment or their PFGE type.

scholarly journals Genetic relationships amongNeisseria gonorrhoeaeserovars analysed by multilocus enzyme electrophoresis

1992 ◽  
Vol 108 (1) ◽  
pp. 31-38 ◽  
Author(s):  
C. L. Poh ◽  
J. C. Ocampo ◽  
G. K. Loh
Keyword(s):  
Genetic Diversity ◽  
Neisseria Gonorrhoeae ◽  
Genetic Relatedness ◽  
Genetic Relationships ◽  
Electrophoretic Analysis ◽  
Enzyme Electrophoresis ◽  
Enzyme Locus ◽  
Multilocus Enzyme Electrophoresis ◽  
Enzyme Loci ◽  
The Mean

Multilocus enzyme electrophoretic analysis was employed to assess the genetic relatedness ofNeisseria gonorrhoeae. Based on the diversity of electromorphs at 9 enzyme loci, 16 electrophoretic types (ETs) were estabilished amongst the 65 isolates. The average number of alleles per enzyme locus was 1·7 and the mean genetic diversity per locus was 0·212. The majority of isolates belonged to either ET1 (32·3%) or ET2 (16·9%). No specific correlation of ETs was seen with serovars as the major types, ETs 1 and 2, were found distributed amongst the various serovars. Major serovars such as Bacjk (IB-1/2) and Bajk (IB-3/6) were each represented by 6 or 8 ETs respectively. Analysis of the genetic relationships of ETs to each other showed some clustering of subgroups that were more closely related than others.

scholarly journals Continued emissions of carbon tetrachloride from the United States nearly two decades after its phaseout for dispersive uses

2016 ◽  
Vol 113 (11) ◽  
pp. 2880-2885 ◽  
Author(s):  
Lei Hu ◽  
Stephen A. Montzka ◽  
Ben R. Miller ◽  
Arlyn E. Andrews ◽  
John B. Miller ◽  
...  
Keyword(s):  
United States ◽  
Carbon Tetrachloride ◽  
San Francisco ◽  
Environmental Protection Agency ◽  
Gulf Coast ◽  
The United States ◽  
Bay Area ◽  
The Us ◽  
Atmospheric Observations ◽  
Surrounding Areas

National-scale emissions of carbon tetrachloride (CCl4) are derived based on inverse modeling of atmospheric observations at multiple sites across the United States from the National Oceanic and Atmospheric Administration’s flask air sampling network. We estimate an annual average US emission of 4.0 (2.0–6.5) Gg CCl4 y−1 during 2008–2012, which is almost two orders of magnitude larger than reported to the US Environmental Protection Agency (EPA) Toxics Release Inventory (TRI) (mean of 0.06 Gg y−1) but only 8% (3–22%) of global CCl4 emissions during these years. Emissive regions identified by the observations and consistently shown in all inversion results include the Gulf Coast states, the San Francisco Bay Area in California, and the Denver area in Colorado. Both the observation-derived emissions and the US EPA TRI identified Texas and Louisiana as the largest contributors, accounting for one- to two-thirds of the US national total CCl4 emission during 2008–2012. These results are qualitatively consistent with multiple aircraft and ship surveys conducted in earlier years, which suggested significant enhancements in atmospheric mole fractions measured near Houston and surrounding areas. Furthermore, the emission distribution derived for CCl4 throughout the United States is more consistent with the distribution of industrial activities included in the TRI than with the distribution of other potential CCl4 sources such as uncapped landfills or activities related to population density (e.g., use of chlorine-containing bleach).

scholarly journals Genetic relationships among strains ofNeisseria meningitidiscausing disease in Italy, 1984–7

1991 ◽  
Vol 106 (1) ◽  
pp. 143-150 ◽  
Author(s):  
P. Mastrantonio ◽  
M. E. Congiu ◽  
R. K. Selander ◽  
D. A. Caugant
Keyword(s):  
Neisseria Meningitidis ◽  
Meningococcal Disease ◽  
Genetic Relationships ◽  
Enzyme Electrophoresis ◽  
Phenotypic Characteristics ◽  
Genetic Features ◽  
Single Clone ◽  
Epidemiological Pattern

SUMMARYSince 1984 a change in the epidemiological pattern of meningococcal disease in Italy has occurred with a predominance ofNeisseria meningitidisof serogroup C (76%), serotype 2a and a high proportion of strains resistant to sulphonamides (71%). In order to understand better the epidemiology of the groupC N. meningitidisstrains responsible for the disease over the last years in Italy, we studied the genetic features of phenotypically closely related strains, by enzyme electrophoresis. The results showed that the genetic and the phenotypic characteristics of the 57 strains studied were similar, suggesting the spread of a single clone during recent years in our country.This result is in agreement with the circulation of strains typical of epidemic situations, despite the decreasing incidence of meningoccal disease in Italy.

scholarly journals Genetic relationships amongEscherichia coliisolates causing urinary tract infections in humans and animals

1989 ◽  
Vol 102 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Thomas S. Whittam ◽  
M. L. Wolfe ◽  
R. A. Wilson
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Genetic Relationships ◽  
Enzyme Electrophoresis ◽  
Bootstrap Analysis ◽  
Multilocus Enzyme Electrophoresis ◽  
Total Genetic Diversity ◽  
Major Cluster ◽  
The Common ◽  
Tract Infections

SUMMARYGenetic variation in isolates ofEscherichia coliobtained mostly from urinary tract infections in humans and domesticated animals (dogs and cats) was assessed for 16 enzymes using multilocus enzyme electrophoresis to characterize chromosomal genotypes. A total of 148 isolates comprised 63 distinct electrophoretic types (ETs) and about half of the isolates belonged to one of 9 common ETs. A bootstrap analysis of genetic distance between ETs revealed three significant groups of strains. Variation in allele frequencies among groups accounted for 40% of the total genetic diversity. The majority of the common ETs fell into a major cluster of closely related strains. The recovery of multiple isolates of the same electrophoretic types and serotypes from unassociated hosts suggests that these bacteria represent uropathogenic clones that are widely disseminated in humans and animals

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